Fry the bacon bits in the pan for a couple of minutes to leave the flavors in the pan, then remove and set aside for later.
Add the olive oil, chopped onion, chopped potato, the first half of the chestnuts, and, the chopped red chili pepper. to the heat and fry for a few minutes
Add the water and allow it all to come to a boil.
Simmer on low heat for 20 minutes, so everything is cooked through.
Remove from the heat and allow to cool for 15 minutes before using a hand blender to make the soup smooth.
Add the bacon bits, the remaining chestnuts chopped into little chunks, and the cannellini beans. Warm through for a further 5 minutes.